Farmers' perceptions have contributed to the understanding of the pest status of Zonocerus variegatus in the humid forest zone of Southern Cameroon. Farmers rate Z. variegatus as an important polyphagous pest on food crops that warrants urgent management or control. The pest incidence has increased because of deforestation and increase of herbaceous fallows. It is therefore necessary to also consider this grasshopper among the major pests in the national strategies of plant protection. Integrated Pest Management (IPM) strategy is a comprehensive approach that combines all rational strategies to reduce pest densities to tolerable levels while maintaining a safe quality environment . These farmers' perceptions are in general similar to the results of most experimental studies but may stimulate researchers to identify new research areas. Farmers' perception can differ profoundly from scientific knowledge, having significant implications for development . Both farmers and scientific knowledge have strengths and weaknesses .
The present study was supported by Grants from Weed and vegetation program (1228 budget) of International Institute of Tropical Agriculture-Humid Forest Ecoregional Center. We thank Dr Denis Sonwa (IITA-STCP-Cameroon), Dr Ousmane Coulibaly (IITA-Benin), Dr Chimère Diaw (CIFOR-Cameroon), Dr Nelson Ntonifor (University of Buea) and Dr Omer Njajou (University of California, San Francisco) for reading and commenting on the manuscript.